\vsssub
\subsubsection{~The Garden Sprinkler Effect} \label{sub:num_GSE}
\vsssub

\noindent
The higher-order accurate propagation schemes are sufficiently free of
numerical diffusion for the so-called `Garden Sprinkler Effect' (GSE) to
occur, i.e., a continuous swell field disintegrates into a set of discrete
swell fields due to the discrete description of the spectrum
\citep[Fig.~3c]{art:BH87}. Several GSE alleviation methods are available in
\ws, as described in the following sections.
